THIS invention relates to a process for the preparation of a vanadyl sulphate solution.
It is known to produce vanadyl sulphate by dissolving vanadium pentoxide in hot dilute sulphuric acid under vigorous agitation and continued heating with the aid of sulphur dioxide as a reducing agent.
The limited solubility of sulphur dioxide in acidic and aqueous solutions results in the emission of sulphur dioxide from the solution and this presents an environmental hazard. Overdosing of the solution with SO2 gas results in the unwanted formation of the lower valent vanadium sulphate, namely V2SO4 and not vanadyl sulphate (VOSO4).
Since the dissolution of vanadium pentoxide in sulphuric acid is endothermic heat has to be provided to drive the formation of vanadyl sulphate.
There is thus always a need for a new method for the production of vanadyl sulphate.